package com.ruoyi.framework.encryption;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
 
import org.apache.commons.codec.binary.Base64;

import java.security.SecureRandom;


/**
 * 前后端数据传输加密工具类
 * @author monkey
 *
 */
public class AesEncryptUtils {
 
    //参数分别代表 算法名称/加密模式/数据填充方式
    private static final String ALGORITHMSTR = "AES/ECB/PKCS5Padding";
 
    /**
     * 加密
     * @param content 加密的字符串
     * @param encryptKey key值
     * @return
     * @throws Exception
     */
    public static String encrypt(String content, String encryptKey) throws Exception {
        KeyGenerator kgen = KeyGenerator.getInstance("AES");
        kgen.init(128);
        Cipher cipher = Cipher.getInstance(ALGORITHMSTR);
        cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(encryptKey.getBytes(), "AES"));
        byte[] b = cipher.doFinal(content.getBytes("utf-8"));        // utf-8
        // 采用base64算法进行转码,避免出现中文乱码
        return Base64.encodeBase64String(b);
    }


    /**
     * 加密  -- 返回16进制字符串
     * @param content 加密的字符串
     * @param encryptKey key值
     * @return
     * @throws Exception
     */
    public static String encryptHex(String content, String encryptKey) throws Exception {
        KeyGenerator kgen = KeyGenerator.getInstance("AES");
        kgen.init(128, new SecureRandom(encryptKey.getBytes()));
        SecretKey secretKey = kgen.generateKey();
        byte[] enCodeFormat = secretKey.getEncoded();
        SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
        Cipher cipher = Cipher.getInstance("AES");// 创建密码器
        byte[] byteContent = content.getBytes("utf-8");
        cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化
        byte[] result = cipher.doFinal(byteContent);
        return parseByte2HexStr(result); // 加密
    }


    /**
     * 解密
     * @param encryptStr 解密的字符串
     * @param decryptKey 解密的key值
     * @return
     * @throws Exception
     */
    public static String decrypt(String encryptStr, String decryptKey, String AESDecryptionCharacterSet) throws Exception {
        KeyGenerator kgen = KeyGenerator.getInstance("AES");
        kgen.init(128);
        Cipher cipher = Cipher.getInstance(ALGORITHMSTR);
        cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(decryptKey.getBytes(), "AES"));
        // 采用base64算法进行转码,避免出现中文乱码
        byte[] encryptBytes = Base64.decodeBase64(encryptStr.getBytes(AESDecryptionCharacterSet));        // utf-8
        byte[] decryptBytes = cipher.doFinal(encryptBytes);
        return new String(decryptBytes);
    }

    /**
     * 解密 -- 解密的字符串
     * @param encryptStr 解密的字符串
     * @param decryptKey 解密的key值
     * @return
     * @throws Exception
     */
    public static String decryptHex(String encryptStr, String decryptKey, String AESDecryptionCharacterSet) throws Exception {
        KeyGenerator kgen = KeyGenerator.getInstance("AES");
        kgen.init(128, new SecureRandom(decryptKey.getBytes()));
        SecretKey secretKey = kgen.generateKey();
        byte[] enCodeFormat = secretKey.getEncoded();
        SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
        Cipher cipher = Cipher.getInstance("AES");// 创建密码器
        cipher.init(Cipher.DECRYPT_MODE, key);// 初始化
        byte[] decryptResult = cipher.doFinal( parseHexStr2Byte(encryptStr) );
        return new String(decryptResult, AESDecryptionCharacterSet); // 加密
    }




    /**
     * 将二进制转换成16进制
     *
     * @param buf
     * @return
     */
    public static String parseByte2HexStr(byte buf[]) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < buf.length; i++) {
            String hex = Integer.toHexString(buf[i] & 0xFF);
            if (hex.length() == 1) {
                hex = '0' + hex;
            }
            sb.append(hex.toUpperCase());
        }
        return sb.toString();
    }


    /**
     * 将16进制转换为二进制
     *
     * @param hexStr
     * @return
     */
    public static byte[] parseHexStr2Byte(String hexStr) {
        if (hexStr.length() < 1)
            return null;
        byte[] result = new byte[hexStr.length() / 2];
        for (int i = 0; i < hexStr.length() / 2; i++) {
            int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
            int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2), 16);
            result[i] = (byte) (high * 16 + low);
        }
        return result;
    }



}